Tamiya 84425 Aluminum Lower Gearbox - TB Series Upgrade  [84425]

Stiffen Your TB Chassis with a Machined Lower Gearbox

If you want a durable upgrade for TB series models, the Tamiya 84425 Aluminum Lower Gearbox replaces the stock plastic lower shell to deliver improved drivetrain efficiency and added rigidity. It is made to fit TB-03, TB-04 and TB Evo.6 chassis, giving a more secure mounting point for suspension and upper components.

Benefits of Aluminum Construction

Machined aluminum increases structural strength compared to the factory plastic piece and gives a neater finish. Swapping in this lower gearbox sharpens the connection for damper stays and upper mounts, helping the car stay composed under load.

Front and Rear Fitment Details

This lower gearbox suits both front and rear positions on TB-03, TB-04 and TB Evo.6 cars, making it a versatile upgrade whether you race on carpet, clay or street circuits. It improves reliability and helps maintain drivetrain alignment during hard cornering.